POS1252 CALIPER PARAMETERS AS PREDICTORS OF MORTALITY IN SYSTEMIC SCLEROSIS: A LONGITUDINAL STUDY
Authors: F. Godinho De Amorim, C. Verrastro, E. Santos, C. Kayser
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). High-Resolution Computed Tomography (HRCT) and pulmonary function tests (PFTs) are useful for the diagnosis and follow-up of ILD, but have limitations for assessing disease severity and progression, including poor reproducibility of the extent analysis by HRCT and low sensitivity of PFTs. Quantitative CT (QCT) methods, including Computed Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER), are new tools that objectively measures parenchymal abnormalities and vascular features on CT images in a fully automated analysis.<sup>[1]</sup> This may bring benefits in detecting early disease and in the assessment of prognosis of patients with SSc-ILD. <h3>Objectives</h3> We investigated whether changes in parenchymal abnormalities measured by CALIPER are associated with mortality and their correlation with PFTs. <h3>Methods</h3> Seventy-one patients diagnosed with SSc (ACR/EULAR 2013 criteria) consecutively evaluated from January 2011 to October 2022 at the Scleroderma outpatients clinic at Federal University of São Paulo were retrospectively selected. To be included, patients should have volumetric HRCTs and PFTs performed at baseline and at 24 months of follow-up. All causes of death and clinical variables were collected from clinical records. HRCTs were analyzed using CALIPER. The following parameters were evaluated: ground glass opacities, reticular pattern, honeycombing, and pulmonary vascular volume (PVV), quantified and normalized to total lung volume (LV) and expressed as a percentage. The extent of ILD (ILD-extent), given by the sum of ground glass, reticular pattern and honeycombing and the fibrosis score given by the sum of the reticular pattern and honeycombing were also evaluated. The best thresholds for CALIPER measurements were calculated using ROC analysis. Factors associated with death were evaluated by Kaplan-Meier survival curves. <h3>Results</h3> Of the 71 SSc patients included the mean age was of 54.2 ± 11.6 years, (mean disease duration of 10 years) and 90.1% were females. Eleven patients (15.49%) died during follow-up and all had ILD. Most of the CAPILER variables remained stable over time (Table 1). All CALIPER parameters (except honeycombing), had a significant correlation with forced vital capacity (FVC) at baseline and follow-up (p&lt;0.001). As shown by Kaplan-Meier survival curves, survival was worse among patients with ILD-extent% ≥ 6.32, fibrosis score% ≥ 1.42 and reticular pattern% ≥ 1.41 at baseline, and an ILD-extent% ≥ 4.75, a fibrosis score% ≥ 0.77, a reticular pattern% ≥ 4.34 and a PVV/LV% ≥ 2,8 at 24 months follow-up (Figure 1). <h3>Conclusion</h3> CAPILER is a useful tool for assessing lung damage and predict mortality in patients with SSc. Future studies are needed to confirm these data. <h3>Reference</h3> [1]Joseph, J, et al. Automated quantitative computed tomography versus visual computed tomography scoring in idiopathic pulmonary fibrosis. J thorac imaging 2016; 31:304-11. <h3>Acknowledgements</h3> We would like to thank Viziomed and the Department of Radiology at Unifesp for their partnership. <h3>Disclosure of Interests</h3> None Declared.